Automatic train control



July 5, 1927. 1,634,691

D. H. SCHWEYER AUTOMATIC TRAIN CONTROL Filed April 26, 1924 2 Shets-Sheet 1 FIG.E

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" e 15/ I h Quorum July 5, 1927. 1,634,691

D. H. SCHWEYER AUTOMATIC TRAIN CONTROL Filed April 26, 1924 2 Sheets-Sheet 2 Patented July 5, 1927.

UNITED STATES DANIEL HERBERT SCHWEYER, OF EASTON, PENNSYLVANIA.

AUTOMATIC TRAIN CONTROL.

Application filed April 26, 1924. Serial No. 709,140.

The present invention relates to automatic train control, and aims to provide a novel and improved apparatus for the continuous automatic control of the movement of a vehicle along a track.

t is the primary object of the invention to provide a continuous automatic control apparatus of the ,kind indicated which is simple in construction and operation, which can be readily installed and maintained in practical service, and which uses the rails and vehicle wheels as the cooperating elements between the vehicle and track, without employing ramps, trips, induction de vices, or the like.

A further object is the provision of suchan apparatus which utilizes,,if so desired, the signal circuits of the track for supplying energy to the vehicle equipment for, controlling the movement of the vehicle according to the condition of the track circuits.

A still further object is the utilization of audion valves controlled by electrical current from the rails of the track and in turn controlling the signalling or controlling means of the vehicle.

It is also an object of the invention to provide an apparatus which is operable for three conditions of control, such as clear, caution and danger, combined with continuousv control, so as to facilitate trafiic by eliminating unnecessary retarded movements.

VJith the foregoing and other objects in View, which will be apparent as the description proceeds, the invention resides in the construction and arrangement'of parts as hereinafter described and claimed, it being understood that changes can be made within the scope of what is claimed, without departing from the spirit of the invention.

The invention is illustrated in the accompanying drawings, wherein V Figure 1 is a diagrammatical view of one form of apparatus embodying the improvements, forthree condition control.

Fig. 2 is a similar View of a modified form of apparatus for three condition control.

Fig. 3 is a diagrammat'ical view of a two condition control apparatus corresponding with the apparatus shown in Fig. 1.

Fig. 4 is a similar View of a two condition control apparatus corresponding with the apparatus shown iii Fig. 2.

In accordance with the practice in railway signalling, the rails 11 and 12 of each block are insulated from the rails of the adjacent blocks, the track being divided into blocks of suitable length. An electromagnet 13 is bridged across the rails 11 and 12 of each block at the entrance end of the block, and a battery 14 or other suitable source of electrical energy is bridged across the rails of the block at the exit end of the block. Said battery. and magnet may be those as customarily used in the wayside signal apparatus, so that no additional track equipment will be necessary for the purposes of this invention, with the exception oi the use of a polarizing switch 15 for reversing the flow ofcurrent in the rails. The switch 15 is connected to the opposite poles of the battery 14 and is controlled by'the magnet 18 of the next block ahead, so that each magnet 13 controls the switch 15 of the block in rear. Conductors or leaders 16 and 17 are connected to the rails 11 and 12 of each block at the exit end of the block and the switch 15 connects said conductors alternately with the poles of the battery 14. Thus, when the magnet 13 of the block ahead is energized, the switch 15. connects the conductor 16 andrail 11 with the positive pole or" the battery-14 and connects the conductor 17 and rail 12 with the negative pole of the battery, so that the current flows from the battery along the rail 11 and returns by way of the rail 12. When the magnet 13 is deenergized, the switch 15 is released and reverses the flow of current, the conductor 17 and rail 12 now being connected to the positive pole of the battery while the conductor 16 and rail 11 are connected to the negative pole. WVhen the block is unoccupied, whether the current flows in one direction or the other, the magnet 13 of the corresponding block will be energized to at tract the switch 15 of the next block in rear, but when the block is occupied so that the vehicle trucks bridge the rails 11 and 12and short circuit the magnet 13, said magnet is deenergized to release the switch of the block in rear so as to reverse the flow of current in the rails of said block in rear.

Two wheels 18 and 19 of the locomotive or vehicle at the opposite sides thereof are used for picking up the electrical current from the rails. The wheels 18 and 19 are regular wheels of the locomotive or vehicle, preferably at the front end thereof, but special wheels or contact members can be provided. The wheels 18 and 19 roll on and have electrical contact with the respective rails 11 and 12, and constitute the terminals of the primary circuit of the vehicle equipment.

The vehicle equipment includes electromagnets 20 and 21 which may control signals or vehicle controlling means, such as a: pneumatic equipment as disclosed in my application Serial No. 698,533, filed March 11, 1924. The magnet 20 when energized either signals clear conditions or controls the vehicle for clear conditions, and the magnet 21 when energized, with the magnet 20 deenergized, signals caution conditions or establishes such conditions of vehicle control, while danger conditions are indicated or obtained when both magnets are deenergized. For the consideration of the present improvements, the magnets or other translating means 20 and 21 may be signal magnets, although it will be understood that they may control the movement of the vehicle through suitable control apparatus, such as disclosed in the aforesaid application.

Electric valves 22 and 23 are employed for controlling the magnets 20 and 21, respectivelyfsaid valves being electron tubes or audions such as used in radio receiving sets. The two valves control the flow of current in the magnets 20 and 21, and said valves are in turn controlled by current flowing in the railsll and 12.

rhe filament or thermal electrode 24 of the valve 22 is connected in circuit with the battery 25 and rheostat 26, for heating the filament, and the plate or positive electrode 27 is connected in circuit with the magnet 20 and the battery 28. Thus, a conductor 29 connects the plate 27 and magnet 20, the conductor 30 connects said magnet and the positive pole of the battery 28, and conductors31 and 32 connect the negative pole of said battery and the negative side or terminal of the filament 24.

The filament and plate circuits of the valve 23 are similar to those of the valve 22. Thus, the filament or thermal electrode 34 of the valve 23 is connected in circuit with the battery 35 and rheostat 36, and the plate 37 is connected in circuit with the magnet 21 and battery 38. Thus, a conductor connects the plate 37 and magnet 21, a conductor 40 connects the magnet 21 and positive pole of the battery 38, and conductors 41 and 42 connect the negative pole of said battery and negative side or terminal of the filament 34.

A conductor 43 connects the wheel 19 with the conductors 31 and 32, and the grid or positive electrode 44 of the valve 22 is connected by a conductor 45 with the conductors 41, 42 and 46, said conductor 46 being connected to the wheel 18, whereby the grid 44 is disposed in a circuit with the wheels or contact members 18 and 19. The filament or positive electrode 47 of the valve 23 is connected by a conductor 48 with the conductor 32, so that the grid of the valve 23 is also connected in circuit with the Wheels 18 and 19, the grids 44 and 47 being connected to the opposite wheels, while the corresponding filament 01": each valve .is connectecl to that wheel opposite to the wheel to which the grid is connected. The filaments 24 and 34 of the valves are negative electrodes for the plates and grids of the corresponding valves.

Operation.

Clear conditions: When the vehicle is traveling in a block by itself, with the block ahead unoccupied, the magnet 13 of the block ahead is energized so that the switch- 15 of theoccupied block is raised to connect the rails 11 and 12 with the positive and negative poles of the battery 14. Although theaxle of the wheels 18 and 19 serves as a short connection between the rails 11 and 12, to deenergize the magnet 13 of the occupied block for reversing the flow of current of the block in rear, a utilizable quantity of current will flowin the vehicle circuit. With the rail 11 charged by positive electrical energy and the rails 12 connected to the negative pole of the battery, current will flowfrom the battery 14 in the circuit including the conductor 16, rail 11, wheel 18, conductor 46, conductor 45, grid '44, filament 24, conductor 32, conductor 43,

wheel 19, rail 12 and conductor 17. The flow of current from the grid 44 to the filament 24 will decrease the resistance in the gap between the plate 27 and filament 24, so that current from the battery 28 will flow through the magnet 20, the circuit including the conductor 30, magnet 20, conductor 29, plate 27, filament 24 and conductors 32 and 31. The magnet 20 is therefore energized to indicate or establish clear conditions in the vehicle equipment. The grid 47 be ing connected with the negative side of the battery 14, while the filament 34 is connected to the positive side of said battery, will oppose the flow of current from the plate 37 t0 the filament 34, so that the magnet 21 remains deenergized. The clear conditions are maintained throughout the block, but may be changed to caution or danger conditions at any time or atany position of the vehicle in passing along. the block.

Caution, conditions: It the block ahead is occupied, so that the magnet 13 thereof is deenergized, the switch of the block n which the vehicle in question is travelling is released, so that the rails 11 and 12 are now connected to the negative and positive poles of the battery 14. This reverses the flow of current in. the rails and primary vehicle circuit, and the grid 44 is now connected with the negative pole of the battery 14 while the grid 47 is connected to the positive pole of said battery. Accordingly, the flow of current from the grid 44 to the filament 24 is stopped, thereby arresting the flow of current from the plate 27 to the filament 24, so that the magnet becomes deenergized. Current will flow from the grid 47 to the filament 34, however, the circuit including the battery 14, conductor 17 (with the switch 15 to the right), rail 12, wheel 19, conductors 43', 32 and 48, grid 47, filament 34, conductors 42 and 46, wheel 18, rail 11 and conductor 16. The fiow of current from the grid 47 to the filament 34 decreases the resistance in the gap between the plate 37 and filament 34, so that current flows from the battery 38 through the magnet 21 in the circuit including the conductor 40, magnet V 21, conductor 39, plate 37, filament 34 and conductors 42 and 41. Accordingly,tl1e reversal of flow of current in the rails, will deenergize the magnet 20 and energize the magnet 21, to indicate or establish caution conditions. However, if the block ahead is vacated by the vehicle therein, so that the magnet 13 of the block ahead is reenergized, clear conditions will be immeditely established by connecting the rails 11 and 12 with the positive and negative poles of the battery 14.

Dcmger c0ncZz'tz'0ns.-Should the vehicle enter a block wvliicli is already occupied, then danger conditions will be established. As hereinbefore described, the vehicle when traveling in a block immediately behind an occupied block, will establish caution conditions,'so that the engineer will be forewarned of a vehicle or train in advance. However, it the second vehicle moves into the block occupied by another vehicle, or should two vehicles simultaneously enter the same block from opposite ends, then the first vehicle will establish a short circuit between the rails 11 and 12to cut off practically all current from the circuit of the second-vehicle as well as from the magnet 13. The first vehicle being closer to the battery '14 will receive the available energy therefrom, while the second vehicle will receive substantially no energy from the rails, being further away from the source of current, with the resistance of 'the rails 11 and 12 also interposed in the circuit of the second vehicle in rear of the first vehicle. Accordingly, the primary circuit of the second vehicle will receive no appreciable electrical current from the track, so that the flow of current from the grid to the filament of either valve is stopped, and both magnets 20 and 21 become deenergized thereby indicating or establishing danger conditions. Such conditions are also established by failure of the batteries, breaking of conductors or wires, short circuits or similar contingencies, so that failures are on the side of safety. The

control is continuous inasmuch'as the change from one condition to either of the others is instantaneous at any position of a vehicle :in the block. This will enable the vehicle to proceed under clear conditions for the remaining distance in a block after the caution or danger conditions have been removed. For example, if one train is following another and the first train advances far enough ahead or is side-tracked, then the second train can immediately proceed without restriction as to speed. The reverse is also true, inasmuch as a vehicle traveling in the block under clear conditions may receive either a caution or a' danger indication'if the block ahead or the same block 1S 6Ilt616Cl by another vehicle or train.

what difi'erent from that of the first form.

Thus, the conductor 16 is connected to the rail ll -or l2 at the exit end of theblock, while the conductor 17 is connected to the other rail at the entrance end of the block. As shown, the conductor 16 is connected to the rail 12 and the conductor 17 is connected to the rail 11, but as indicated at 16 and 17, said conductors can be connected to the opposite rails, or multiple connections may be used.

WVhen the magnet 13 is energized and the switch 15 is raised, the current from the battery 14 flows in the circuit including the conductor 16 rail 12, wheel 18 conductors 46 42 and grid 44, filament 24 conductors 32 and 43, wheel 19, rail 11 and conductor 17 so that current flows from the plate 27 to the filament 24 to energizethe magnet 20*. When the magnet 13 is decnergized, the fiow of current is reversed, and current now flows from the battery '14 INS in the circuit including the conductor 17 rail 11, wheel 19 conductors 43, 31 and 48. grid 47, filament 34", conductors 42 and 46, wheel 18, rail 12, and conductor 16*. The current can now fiow from the plate 37 to the filament 34 to energize the mag net 21, while the magnet 20 is deenergized in substantially the same manner as in the apparatus shown in Fig. 2. Danger'conditions are established when the vehicle enters a block already occupied, inasmuch as the flow of current is so reduced that the magnets 20 and 21 are deenergized.

Fig. 3 shows a two condition control apparatus corresponding with the apparatus shown in Fig. 1. The polarized track circuit is eliminated, and themagnet 13 controls simple make and break switch 15 for the battery 14 and the vehicle equipment in cludes a single electromagnet 20 "and a, single valve 22". Vfhen the magnet 13 is energized the switch 15 is closed, the current from the battery 14 flows in the circuit in cluding the conductor 16, rail 11, wheel 18", conductor 46 grid 44", filament 24 conductors 32 and 43, wheel 19 rail 12 and conductor 17*. The current therefore fiows from the plate 27 b to the filament 24 so that the magnet 20 is energized from the battery 28 to indicate or establish clear conditions.

When the magnet 13 is deenergized or the block is already occupied, or should the circuit be shorted or broken, the current from the battery 14 would be shut off from the grid 44*, thereby stopping the flow of current between the plate 27 and filament 24 so that the magnet 2O will be deenergized to indicate or establish danger conditions.

Fig. 4 shows simplified form of the apparatus shown in Fig. 2, for two condition control, a simple make and break switch 15 being employed and the conductors 16 and 17 being connected to the exit and entrance ends of the rails, with the conductors 46 and 43 connected to the wheels 18 and 19 at longitudinally spaced points of the track. When the switch is closed the current from the battery 14 flows in the circuit including the conductor 16 rail 12 wheel 18, conductor 46, grid 44, filament 24, conductors 32 and 43, wheel 19", rail 11 and conductor 17 so that current flows from the plate 27 c to the filament 24 to energize the magnet 20"- When the switch 15 is open or current from the battery 14 otherwise shut ofi from the valve 22 then this will arrest the flow or current in the circuit of the magnet 20 so that said magnet is deenergized for indicating or establishing danger conditions.

Fig. 5 shows how the energy "from the track can be amplified so that a feeble current from the rails can be stepped up for the effective control of the signal or control magnet. As shown, there are two stages of amplification although there may be any number. Audion or similar electrical valves 50 and 51 are employed between the valve 22 and magnet 20 The filament 24 is in the circuit with the battery 25 and rheostat 26. The primary control circuit includes the wheel or contact member 18 conductor 46, grid 44 filament 24 conductor 43 and rail or contact member 19 so that the current flows from the grid 44 tothe filament 24 The filaments 52 and 53 of the valves and 51 are disposed in the respective circuits with the batteries 54 and 55 and rheostats 56 and 57. The flow of current from the grid 44 to the filament 24 will establish the fiow oft current "from the plate 27 to the filament 24 in the circuit including the battery 61, conductor 60, grid 59 or" the valve 50, filament 52, conductor 58, plate 27 filament 24 andconductor 62. The current flowing in such circuit from the battery 61 is of greater E. M. F. than the current flowing in the primary circuit. The current flowing from the grid 59 to the filament 52 will establish the flow of current from the plate 63 of the valve 50 to the filament 52, such circuit including the battery 68, conductor 67, filament 66 of valve 51, filament 53, conductor 64, plate 63, filament 52 and conductor 69. The current flowing in this circuit is of still greater E. M. F., and will establish the flow of still stronger current from the plate 70 of the valve 51 to the filament 53, such circuit including the battery-7 3, conductor 72, magnet 20 conductor 71, plate 70, filament 53 and conductor 74. Thus, by using a suitable number of stages of amplification, the electrical energy can be gradually increased until suflicient to control the magnet 20 properly, even though the electrical energy received from the rails is feeble because of the primary circuit being shorted by the axles of the wheels.

Fig. 6 illustrates a further development of the track circuits. Three blocks are shown, designated E, F, and G, including the respective rails 11 12 11 12 and 11 12 The track circuits for the block F are shown completely, but it will be understood that the circuits for each block are the same. Electromagnets 13 and 13 are bridged across the rails 11 and 12 at the entrance end of the block F, and a track battery 14 is provided to be bridged across said rails at the exit end of said block. A neutral relay and a polarized reversing relay control the fiow of current from the battery 14 through the rails 11 and 12 The neutral relay includes the switch 15 controlled by the primary magnet 13 of the block G, and the polarized reversing relay includes the reversing switch 1'5 controlled by the secondary magnet 13 ofthe block H (not shown) beyond the block G. Said switches 15 and 15 are disposed between the conductors 16 -47 and the battery 14. In the same way, the battery 14? of the block E is controlled by a neutral switch 15 and the polarized reversing switch 15". The switch 15 is controlled by the primary magnet 13 of the block F, while the switch 15 is controlled by the secondary magnet 13 of the block G.

When the blocks are clear, the magnets are energized, thereby closing the neutral switches and moving the'polarized switches toward the left, to connect the positive poles of the batteries to the rails 11", 11, etc, and to connect the opposite rails with the negative poles of the batteries. Supposing the block G to be occupied, the magnets 13 and 13? are deenergized, so that the switch 15 drops open and the switch 15 moves toward the right. The switch 15 being opened will shut off current from the rails 11 and 12 so that the vehicle travelling in the block F will receive a danger signal'or indication, by failure to receive current from the battery 14?. The switch 15 being moved toward the right will reverse the flow of current from the battery l f in the rails 11 and 12 so that a vehicle travelling in'the block E' will receive a caution signal or indication. The vehicle equipment is the same as shown in Fig. 1, but if the vehicle equipment is as shown in Fig. 2, then the conductors 16 -17 16 17 etc.', are connected to the rails at the opposite ends of the block in accordance with the showing in Fig. 2.

If the block F is occupied, then the magnets 13 and 13 are deenergized, and the switch 15 opening will shut OK the track battery current from the rails 11 and 12 so that a vehicle in the block E would receive a danger signal or indication. Thus, a vehicle in a block behind an occupied block will receive a danger signal or condition, while a vehicle in a block which is'two blocks behind an occupied block will receive a caution signal or indication. The conditions are automatically changed the same as hereinbefore described. Thus, if vehicles are in blocks E and F, the vehicle in block'E is under danger control, and if the vehicle in block F moves on into block G, then the vehicle in block E will be changed immediately from danger to caution control, and if the vehicle ahead moves out of the block G, then the vehicle in block E will immediately receive a'clear condition. The reverse is true, inasmuch as a vehicle in the block E will receive caution and then'danger conditions when the blocks Gr and F are occupied in succession by a vehicle approaching the block E. I

Having thus described the invention, what is claimed as new is 1. The combination with the tratfic rails of a track and means for supplying and controlling the flow of electrical current in said rails, of a vehicle equipment including a circuit connected in electrical contact with said rails toreceive current therefrom, two elec trical valves each having three electrodes two of which are connected in said circuit, a circuit for each of said valves including a source of electrical energy and one of said two electrodes and the third electrode of the corresponding valve for thefiow of current in the last named circuit dependent on the flow of current in the first named circuit, and translating means controlled by each of the last named circuits, the valves being arranged to selectively control the last named circuits according to predetermined differences in current in the first named circuit.

2. The combination with the traffic rails of a track and means for supplying and controlling the flow of electrical current in said rails, of a vehicle equipment including a circuit connected in electrical contact with said rails to receive current therefrom, two audion valveseach having a filament, plate and grid with the filament and grid connected in said circuit, a circuit for each valve including a source of electrical energy and the plate and filament of the corresponding valve, and translating means controlled by each of the lastnamed circuits, :saidvalves being so arranged as to selectively control the lastnamed circuits by differences in current flowing in the firstnamed circuit.

3. The combination with. the traflic rails of a track and means for supplying and controlling the flow of electrical current in said rails, of a vehicles equipment including a circuit connected in electrical contact with said rails to receive current therefrom, two other electrical circuits each including a source of electrical energy, two electrical Valves in the firstnamed circuit and control ling the flow of current in the lastnamed circuits according to differences in the flow of current in the firstnamed circuit, and translating means controlled by each of the lastnamed circuits. 4:. The combination with the traffic rails of a track and means for supplying and reversing the flow of electrical current in said rails, of a vehicle equipment including a circuit connected electrically with said rails to receive polarized current therefrom, two electrical circuits each including a source of electrical energy, electrical va],ve means for alternately controlling the flow of current in the lastnamed circuits when the current inthe firstnamed circuit flows in opposite directions, and translating means controlled by the lastnamed circuits.

5. The combination with the traffic rails of a track and means for supplying and reversing the flow of electrical current in said rails, of a vehicle equipment including a circuit connected electrically with said rails to receive polarizeu current therefrom, two electrical circuits each including a source of electrical energy and an electrical valve having three electrodes two of which are connected in the circuit, one or" said two electrodes and the third electrode of each valve being disposed the lirstnamed circuit and being so arranged that the reversal of the current in the firstnamed circuit will alternately control said two circuits, and translating means controlled by said two circuits.

6. The combination with the trafiic rails of a track and means for supplying and Versing the flow of electrical cur'" nt in said rails, of a vehicle equipment including a tillcuit connect-ed electrically with said rails to receive polarized current therefrom, two circuits each including a source of electrical energy and an audionvalve having a n ment, grid and plate with the mate and filament connected in the last in the grids and filaments of the c connected in reverse arrangements in t 1e first named circuit so that the flow of or ii: the first named circuit in opposite direct will alternately control said two circui c, and translating means controlled by said two circuits.

of a track and means -for sup reversing the flow o'l electrica. c said rails, of a vehicle equipment ncluding contact members in electrical with said rails, two circuits e ch i uding a source of electrical energy d an audion valve having a filament, plate and grid with the plate and filament connected in the circuit, the grid or one valve and filament or the other valve being connected to one contact member and the other grid and filament being connected to the other contact member, and translating means controlled by said circuits 8. The combination with a railroad track divided into blocks having the rail" thereof insulated from one another, an electronic. net bridged across the rails oi each block, a source of electrical energy for each block, a reversing switch for connecting the source of'electrical energy with the rails or" block for reversing the flow of current said rails, the switch of ea h block bei controlled by the electroma the ill net or tllQlllOLlK ahead, of a vehicle equipn ent including a circuit connected electrically with the rails to receive polarized current therez'tiom, two circuits each including a source oi e ectrical ener y and a controlling valve, said valves being connected in the firstnained circuit for alternately controlling said two circuits by the reverse flow of current in the firstnamed circuit, and translating means controlled by said two circuits.

9. The combination with the traflic rails of a track and means for supplying and con 10. The combination with the trafiic rails V of a track and means "for supplying and controlling; the direction of fiow of direct electrical current in said rails, of a vehicle equipi'nent, including two audion valves each 'h'avfilament, plate and grid with the filatraffic rails in circuit therewith, a circuit for each valve including a. source of electrical energy and the plate and filament of the corresponding valve, and translating means controlled by each of said circuits, said valves being in reverse arrangement so as to selectivelycontrol said circuits by the fiow of currentin opposite directions in the rails and valves.

11. The combination with the tra-fiic rails of a track and means for supplying and reversing the flow of electrical. current in the rails, of a vehicle equipment including two electrical circuits-including a source of electrical energy, electrical valve means for alternately controlling the flow of current in said circuits and connected electrically in circuit with said rails in reversed arrangements,

and translating means controlled by said cir-' cuits.

12. The combination with thetrafiic rails of track and means for supplying and reversing the flow of electrical current in said rails, of a vehicle equipment having two electrical circuits each including a source of electrical energy, and an audion valve hav-' ing a filament, grid and plate with the plate and filament connected in said circuit, the grids and filaments of the valves being connected in reverse arrangements in electrical circuit'with said rails so that the fiow of current in opposite directions in the rails will alternately control said circuits. and translating means controlled by said circuits.

In testimony whereof I hereunto aflix my signature.

DANIEL rmnennr SGHWEYER, V

and grid connected electrically with said i 

